// The libMesh Finite Element Library.
// Copyright (C) 2002-2025 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



// Local includes
#include "libmesh/quadrature_clough.h"
#include "libmesh/quadrature_gauss.h"
#include "libmesh/enum_to_string.h"

namespace libMesh
{


void QClough::init_2D()
{
#if LIBMESH_DIM > 1
  QGauss gauss_rule(2, _order);
  gauss_rule.init(TRI6, _p_level, /*simple_type_only=*/true);

  //-----------------------------------------------------------------------
  // 2D quadrature rules
  switch (_type)
    {

      //---------------------------------------------
      // Triangle quadrature rules
    case TRI3:
    case TRI6:
    case TRI7:
      {
        std::vector<Point> & gausspoints = gauss_rule.get_points();
        std::vector<Real> & gaussweights = gauss_rule.get_weights();
        std::size_t numgausspts = gausspoints.size();
        _points.resize(numgausspts*3);
        _weights.resize(numgausspts*3);
        for (std::size_t i = 0; i != numgausspts; ++i)
          {
            _points[3*i](0) = gausspoints[i](0) +
              gausspoints[i](1) / 3.;
            _points[3*i](1) = gausspoints[i](1) / 3.;
            _points[3*i+1](0) = gausspoints[i](1) / 3.;
            _points[3*i+1](1) = gausspoints[i](0) +
              gausspoints[i](1) / 3.;
            _points[3*i+2](0) = 1./3. +
              gausspoints[i](0) * 2./3. -
              gausspoints[i](1) / 3.;
            _points[3*i+2](1) = 1./3. -
              gausspoints[i](0) / 3. +
              gausspoints[i](1) * 2./3.;
            _weights[3*i] = gaussweights[i] / 3.;
            _weights[3*i+1] = _weights[3*i];
            _weights[3*i+2] = _weights[3*i];
          }
        return;
      }


      //---------------------------------------------
      // Unsupported type
    default:
      libmesh_error_msg("Element type not supported: " << Utility::enum_to_string(_type));
    }
#endif
}

} // namespace libMesh
